Isolation and identification Avibacterium paragallinarum from layers with infectious coryza symptoms in Sleman District, Special Region of Yogyakarta, Indonesia

Infectious coryza (IC) or snot is one of the upper respiratory diseases of chickens caused by Avibacterium paragallinarum with symptoms of sinus infraorbitalis swelling, lacrimation and malodorous sinus exudate. The disease has high morbidity and causes economic losses in poultry industries. The purpose of this study was to identify A. paragallinarum from layers that showed infectious coryza symptoms. Samples were taken from 12 layers from farms in Sleman District, Special Region of Yogyakarta that showed IC symptoms such as swollen face and malodorous sinus discharge.  The sinus exudates were cultured on chocolate agar plate and incubated in candle jar at 37°C for 24-48 h. Observations were aimed at dew-drop like colony and confirmed for cell morphology (coccobacilli, Gram-negative) with Gram staining. Biochemical tests such as catalase, oxidase, urease, indole, motility and carbohydrates fermentation (glucose, sucrose, lactose, mannitol, maltose, sorbitol, galactose) were carried out to identify A. paragallinarum . This study revealed eight isolates (66,7%) from twelve suspected isolates were identified as A. paragallinarum . Keywords: Avibacterium paragallinarum , identification, infectious coryza, layer